TR&D 2 - Field-cycling relaxometry Summary The ?Center on Macromolecular Dynamics by NMR Spectroscopy? (CoMD/NMR) will install the world's first field-cycling shuttle system for an 800 MHz NMR spectrometer, to be sited at the New York Structural Biology Center. This instrument will enable applications of relaxometry to DBPs, to significantly increase knowledge of the relevant spectral density functions and therefore allow much more detailed investigations of macromolecular conformational dynamics. Relaxometry is a technique in which a sample is polarized at high static magnetic field, then physically moved to low field for a relaxation period, and subsequently returned to high field for detection. Activities in this TR&D will include evaluation of alternative shuttle designs, development of novel experimental strategies for use of the shuttle probe, and iterative development and validation of analysis approaches to interpret relaxometric data for the DBPs.